A filter cigarette making machine has a predetermined conveying path, and cigarette rods are supplied to the conveying path and carried along the carrying path. While carried along the conveying path, each cigarette rod is cut into two equal parts to form two cigarettes.
Then, on the conveying path, a cigarette/plug assembly having a filter plug arranged between two cigarettes is formed. By wrapping a piece of tip paper around the cigarette/plug assembly,. the cigarette/plug assembly is formed into a double filter cigarette. Then, by cutting the double filter cigarette at the center of the filter plug, individual filter cigarettes are obtained.
Generally, a filter cigarette making machine has a drum train, and the drum train forms the conveying path. More specifically, the drum train includes a plurality of grooved drums, and the grooved drums are arranged in line, adjacent to each other. The grooved drum at the beginning end of the drum train is called a catcher drum. The catcher drum is disclosed in Japanese Unexamined Patent Publication No. hei 10-14556, for example.
The catcher drum disclosed in this publication has a plurality of receiving grooves in an outer circumferential surface thereof. The receiving grooves are arranged at regular intervals in the circumferential direction of the catcher drum. As the catcher drum rotates, the receiving grooves pass a receiving position one after another. The receiving position is defined as a predetermined angle position in the direction of rotation of the catcher drum.
When each receiving groove passes the receiving position, a cigarette rod is fed into the receiving groove and received in the receiving groove. The cigarette rod received in the receiving groove moves forward in the groove. While moving forward, braking force from a braking means is applied to the cigarette rod so that the cigarette rod stops at a predetermined position in the receiving groove.
Specifically, the braking means comprises a plurality of suction holes open at the bottom of each receiving groove and a suction source for supplying suction pressure to the suction holes, and the suction pressure brakes the cigarette rod moving forward in the receiving groove.
The cigarette rod in the receiving groove is then pushed back to a normal position by a pusher and placed at the normal position. As a result, the cigarette rod is surely transferred from the catcher drum onto the next grooved drum, which is a transfer drum, and carried along the conveying path.
The position at which the cigarette rod is stopped in the receiving groove by the braking means varies to a large degree even when the speed at which the cigarette rod is fed or the weight of the cigarette rod varies slightly.
Thus, when the cigarette rod is stopped in the receiving groove after overrunning the normal position to a large degree, not only the distance that the cigarette rod slides increases but also the distance that the cigarette rod is pushed back, namely the distance between the position at which the cigarette rod is stopped and the normal position increases. In this situation, the cigarette rod rubs against the inner surface of the receiving groove, and wrinkles are easily formed on the wrapping paper of the cigarette rod.
Meanwhile, when the cigarette rod is stopped in the receiving groove before reaching the normal position, the pusher cannot push back the cigarette rod to the normal position. As a result, the cigarette rod cannot be transferred from the catcher drum to the transfer drum, hence cannot be carried along the conveying path.